The present inventions relate generally to washroom fixtures. The present inventions also relate to a washroom fixture such as a lavatory system having a control system suitable for providing “hands-free” operation of one or more fixtures (e.g., sprayheads, faucets, showerheads, soap or lotion dispensers, hand dryers, flushers for toilets and/or urinals, emergency fixtures, etc.) within the lavatory system. More particularly, the present inventions relate to a lavatory system having a control system utilizing a capacitive sensing system to detect the presence of an object (e.g., the hand of a user, etc.) and actuate the one or more fixtures. The present invention further relates to various features and combinations of features shown and described in the disclosed embodiments. Other ways in which the objects and features of the disclosed embodiments are accomplished will be described in the following specification or will become apparent to those skilled in the art after they have read this specification. Such other ways are deemed to fall within the scope of the disclosed embodiments if they fall within the scope of the embodiments which follow.
It is generally known to provide a lavatory system having at least one fixture that conventionally requires manual manipulation by a user in order to operate. It is further known to provide an electrical and/or electronic control system for providing “hands-free” operation of the fixture. Not requiring a user to physically contact or touch the fixture for its operation may be desirable for various sanitary and/or accessibility considerations.
It is also generally known to provide an electrical and/or electronic control system utilizing an infrared (IR) sensor to detect the presence of an object and actuate one or more fixtures of the lavatory system. Such control systems generally have a transmitter that is configured to emit pulses of infrared light into a sensing region (e.g., an area adjacent to the fixture, etc.) and a receiver that is configured to measure the level of infrared light in the sensing region. Ideally, when an object enters the sensing region, at least a portion of the infrared light emitted from the transmitter will be reflected by the object and detected by the receiver which in turn creates a signal representative of the level of infrared light in the sensing region that can be used to determine whether the fixture should be actuated.
In the case of control systems utilizing an IR sensor, false activations of a fixture and/or a failure to detect an object may arise due to variations in the reflectivity of objects near the fixture and/or damage (e.g., contamination, etc.) of the optics of the IR sensor. False activations may ultimately result in a waste of resources (e.g., water, soap, towels, energy, etc.) that is contrary to the benefits of having a “hands free” operated fixture. Likewise, missed detections may frustrate a user attempting to realize the benefits of the fixture.
An alternative to an IR sensor, is a capacitive sensing system. Capacitive sensing systems generally provide an electric field and rely on a change in the electric field for sensing purposes. While capacitive sensing systems may be advantageous to IR sensors since capacitive sensing systems are not susceptible to false and/or missed detections due to reflectivity variations and/or optic damage, the use of capacitive sensing systems create additional issues. For example, variations in the environment may cause interfering variations in capacitance which may lead to false and/or missed detections. Such variations may be caused by contaminants on the surface of the electrodes or other objects in the electric field, changes in ambient humidity, gradual variations in the proximity or composition of nearby objects, or variations in the sensor mounting locations. All of such variations are likely occurrences in the environment of a lavatory system.
It would be advantageous to provide a lavatory system for use in commercial, educational, or residential applications, having one or more fixtures and a control system for enabling “hands-free” operation of the fixtures wherein the control system utilizes a capacitive sensing system. It would also be advantageous to provide a control system utilizing a capacitive sensing system that is capable of improved sensitivity and reliability, particularly in the typical environment of a lavatory system. It would further be advantageous to provide a control system utilizing a capacitive sensing system that reduces or minimizes the number of missed detections by providing an improved electrode plate configuration. It would further be advantageous to provide a power management system providing for the efficient use of the electrical energy required to operate a control system utilizing a capacitive sensing system, such as electrical energy generated by one or more photovoltaic cells. It would further be advantageous to provide a capacitive sensing system that detects an object within a sensing region regardless of the direction in which the object enters the sensing region, allows for use of a large plate size to maximize the detection signal, does not require the use of a guard plate, is able to extend detection window farther from an output of the fixture, and/or offers less difference between wet and dry conditions.
Accordingly, it would be desirable to provide for a lavatory system and/or capacitive sensing system having one or more of these or other advantageous features. To provide an inexpensive, reliable, and widely adaptable capacitive sensing system for a lavatory system that avoids the above-referenced and other problems would represent a significant advance in the art.